Temperature Controlled Pallet Shipper

ABSTRACT

A thermally insulated pallet shipper is provided for use in any industry where temperature sensitive products are shipped, including the pharmaceutical, hospital and food industries, particularly for shipping payloads by air. The pallet shipper is made from just four individual foam molded structures: a base, a first corner structure, a second corner structure and a lid.

CROSS REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. application Ser. No. 15/012,930, filed Feb. 2, 2016. Application Ser. No. 15/012,930 is a continuation-in-part of U.S. application Ser. No. 14/485,272, filed Sep. 12, 2014, now U.S. Pat. No. 9,272,811, issued Mar. 1, 2016. U.S. application Ser. No. 15/012,930 is incorporated here by reference in its entirety to provide continuity of disclosure.

FIELD OF THE DISCLOSURE

This disclosure relates to a temperature controlled pallet shipper for shipping temperature sensitive payloads. More particularly, this disclosure relates to a temperature controlled pallet shipper that avoids the disadvantages of prior temperature controlled pallet shippers while affording additional structural and operating advantages.

DESCRIPTION OF THE RELATED ART

Temperature controlled shippers are used to ship perishable materials such as pharmaceuticals, blood and blood products, transplant organs and food products which must be maintained within a certain temperature range. The shipping and transportation of various perishable materials frequently requires that such materials be maintained in a stable temperature range either higher or lower than the ambient temperatures to which the packaging will be exposed. A number of different types of thermally insulated containers have been developed for this purpose. They generally fall into two main categories, active shippers and passive shippers.

Active shippers are those in which the internal temperature is controlled using a battery operated device or electrical power cord. These systems usually are expensive and quite bulky.

Passive shippers are those in which the internal temperature is maintained without any battery or electrical support. Therefore passive pallet shippers typically are used for five to seven days of duration while battery and electric operated shippers maintain payload temperature as long as the power supply is active.

Pallet shippers may be made of variety of materials, and choice of a material depends on manufacturer core competency, material insulation properties and choice of design features. The thermal conductivity (sometimes called “k value”) of a material plays a key role. Thermal conductivity is the ability of material to conduct heat, so the lower the k value the better insulation properties. Common materials for making the outer structure of a pallet shipper include polyurethane (PUR), extruded polystyrene foam (XPS), expanded polystyrene foam (EPS) and molded plastic.

The use of most if not all of these passive shippers involve several challenges and problems:

Weight

The majority of passive pallet shippers are transported via air where the weight of the shipper is a critical factor in transportation cost. Depending on the size of pallet shipper, the payload (such as pharmaceuticals) weight can range anywhere from 400 lbs. to 1600 lbs. On top of this, the refrigerant weight can range from 200 lbs. to 1800 lbs. depending on the duration and temperature requirements.

Edge Leaks

Due to their size, pallet shippers are typically made by molding one panel (wall) at a time. The box or outer structure typically is constructed by assembling six walls. Creating a big box with large walls is not easy and can create lot of gaps (edge leaks) between the walls. Edge leaks in general occur when two adjoining walls of material are not completely in contact/flush with one and another and therefore create a visible gap, which creates a path for ambient air to leak into the container. This results in gain or loss of thermal energy by convection into or out of the pallet shipper. The R-value of the system is reduced significantly due to the presence of these leaks.

These leaks have negative impact on insulation properties and effectively reduce duration of a shipper. Simply adding additional thermal insulation to enclosure is of little benefit; the edge gaps must be minimized or eliminated completely in order for the system's R-value to be maintained. Thus designing an edge leak proof box is very desirable.

Manual Labor Requirements

Shipping pallet assembly requires manual labor, typically in the form of one or two people. It is important to keep the assembly process as simple as possible. Adding complexity into the process can create errors (defects) which can result in the loss of millions of dollars of pharmaceuticals.

Transportation Considerations

Some pallet shippers are specially designed to transport pharmaceuticals and other perishable payloads from one continent to other via air. These air cargo pallet shippers, also known as unit load devices (ULDs), generally fall into one of a number of specific categories, including PAG (quarter and half sizes) and PMC (quarter and half sizes).

Requiring couriers to be more gentle or use greater care when handling the pallet shipper is usually beyond the control of the shipper maker or user. By designing a pallet shipper to create a more robust and sturdy structure, the problems associated with transportation and vibration can be mitigated or even eliminated.

The present disclosure is designed to address the problems described above, by describing a pallet shipper that is modular, easily assembled and has superior thermal properties.

BRIEF SUMMARY OF THE DISCLOSURE

The present disclosure relates to an improved temperature controlled pallet shipper that avoids the disadvantages of prior pallet shippers while affording additional structural and operating advantages.

In one aspect the disclosure relates to a pallet shipper for shipping a temperature sensitive payload, the pallet shipper comprising a pallet shipper for shipping a temperature sensitive payload, the pallet shipper comprising a base and two U-shaped structures.

All four vertical corners are solid, continuous corners, meaning that they lack any seams, joints or other discontinuities. The U-shaped structures are joined to each other along convoluted seams located between the vertical corners. Making the seams convoluted and moving them to the middle of the container sides, away from the vertical corners, reduces heat transfer between the outside and the inner, payload compartment.

The pallet shipper has a modular design and can be enlarged from, say, a quarter PMC to a half PMC and from a quarter PAG to a half PAG just by adding a sidewall between the U-shaped corner structures on either side of the pallet shipper.

The modular design is beneficial from both a product cost standpoint and a logistics cost standpoint. For example, a user can stock a quarter PMC part and use it for a half PMC pallet shipper if there is a need. The modular design also helps reduce tooling costs which results in a reduction in product cost.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of a quarter PMC pallet shipper according to the disclosure.

FIG. 2 is an exploded perspective view of the quarter PMC pallet shipper of FIG. 1.

FIG. 3 is a perspective view of a base used in the construction of the quarter PMC pallet shipper of FIG. 1.

FIG. 4 is a perspective view of a first corner structure used in the construction of the quarter PMC pallet shipper of FIG. 1.

FIG. 5 is a perspective view of a second corner structure used in the construction of the quarter PMC pallet shipper of FIG. 1.

FIG. 6 is a perspective view of a portion of the quarter PMC pallet shipper of FIG. 2.

FIG. 7 is a perspective view of a portion of the quarter PMC pallet shipper of FIG. 2.

FIG. 8 is a top perspective view of a portion of the quarter PMC pallet shipper of FIG. 1 with the lid removed.

FIG. 9 is a bottom perspective view of the quarter PMC pallet shipper of FIG. 1.

FIG. 10 is a perspective view of a half PMC pallet shipper according to the disclosure.

FIG. 11 is an exploded perspective view of the half PMC pallet shipper of FIG. 10.

FIG. 12 is a perspective view of a side wall panel used in the construction of the half PMC pallet shipper of FIG. 10.

FIG. 13 is an exploded perspective view of a pallet shipper including wire racking according to the disclosure.

FIG. 14 is a perspective view of an alternative pallet shipper according to the disclosure.

FIG. 15 is a perspective view of the pallet shipper of FIG. 14 shown with one corner structure and the lid removed for clarity.

FIG. 16 is a perspective view of an alternative corner structure.

FIG. 17 is a perspective view of the corner structure of FIG. 16 shown in a flat position.

FIG. 18 is a top view of another alternative pallet shipper.

DETAILED DESCRIPTION OF THE DISCLOSURE

While this disclosure may be embodied in many forms, there is shown in the drawings and will herein be described in detail one or more embodiments with the understanding that this disclosure is to be considered an exemplification of the principles of the disclosure and is not intended to limit the disclosure to the illustrated embodiments.

Turning to the drawings, there is shown in FIG. 1 a perspective view of a pallet shipper 10 (a quarter PMC pallet shipper) for shipping a temperature sensitive payload. FIG. 2 is a partially exploded perspective view of the quarter PMC pallet shipper 10 of FIG. 1. The pallet shipper 10 comprises a substantially rectangular base 12, a substantially rectangular lid 14, two substantially L-shaped, unitary, first corner structures 16, and two substantially L-shaped, unitary, second corner structures 18. Significantly, as explained below, there are no seams or other structural discontinuities at the four outer corners 46, 66. Rather, the seams or junctions are located along the sides of the pallet shipper 10 away from the corners 46, 66. The pallet shipper 10 may be made from foamed insulative materials using only four molding tools, one each for the base 12, lid 14, first corner structure 16 and second corner structure 18.

FIG. 3 is a perspective view of the base 12 used in the construction of the quarter PMC pallet shipper of FIG. 1. The base 12 comprises a rectangular upper portion 20 and a rectangular lower portion 22 located adjacent to and under the upper portion 20. The upper portion 20 extends from a first side edge 24 to an opposite first side edge 26 and from a first front edge 28 to an opposite first rear edge 30. The upper portion 20 has a first width defined by the first side edges 24, 26 and a first depth defined by the first front edge 28 and the first rear edge 30.

The lower portion 22 extends from a second side edge 34 to an opposite second side edge 36 and from a second front edge 38 to an opposite second rear edge 40. The lower portion 22 has a second width defined by the second side edges 34, 36 and a second depth defined by the second front edge 38 and second rear edge 40. As is apparent from the figure the lower portion width is less than the upper portion width and the lower portion depth is less than the upper portion depth, so the lower portion edges 34, 36, 38, and 40 are recessed with respect to the upper portion edges 24, 26, 28, 30.

The peripheral portion of the upper portion 20 extending beyond the lower portion may be referred to as a ledge 31. As perhaps best shown in FIG. 7, the ledge 31 has an underside 32 that slopes downward toward the lower portion 22.

The lid 14 is substantially rectangular and may be constructed similarly to the base 12. The lid fits over and may form a friction fit with corner structures 16, 18.

FIG. 4 is a perspective view of a first corner structure 16 used in the construction of the quarter PMC pallet shipper of FIG. 1. Two are used in the construction of the pallet shipper 10 and may be located diagonally opposite each other. Each first corner structure 16 comprises a grooved panel 42 and a flanged panel 44 orthogonal to the grooved panel 42. The grooved panel 42 and the flanged panel 44 are joined along a vertical corner 46 to form a single unitary structure. Each first corner structure 16 extends from a bottom edge 48 to a top edge 50.

The grooved panel 42 extends from the vertical corner 46 to a distal grooved edge 54. The distal grooved edge 54 defines a vertically oriented groove 56. The flanged panel 44 extends from the vertical corner 46 to a distal flanged edge 58. Each first corner structure 16 has an outer surface 57 (FIG. 2) facing away from the payload and an inner surface 59 facing the payload. An inner flange 60, so called because it can be considered an extension of the inner surface 59, extends from the distal flanged edge 58 in a direction away from the vertical corner 46. The flange 60 helps define an outer notch 61 on the outer surface 59 of the flanged panel 44.

Each first corner structure 16 also comprises an L-shaped footer 52 extending inwardly from the grooved panel 42 and the flanged panel 44 near the bottom edge 48 and terminating in an L-shaped distal edge 51. Each footer 52 has an L-shaped top surface 53 that slopes downwardly toward the distal edge 51.

FIG. 5 is a perspective view of a second corner structure 18 used in the construction of the quarter PMC pallet shipper 10 of FIG. 1. As with the first corner structures 16, two second corner structures 18 are used in the construction of the pallet shipper 10 and are located diagonally opposite each other. Each of the two substantially L-shaped, unitary, second corner structures 18 comprises a tongued panel 62 and a flanged panel 64 orthogonal to the tongued panel 62. The tongued panel 62 and the flanged panel 64 are joined along a vertical corner 66. Like the first corner structures 16, each second corner structure 18 extends from a bottom edge 48 to a top edge 50.

The tongued panel 62 extends from the vertical corner 66 to a distal tongued edge 74. A tongue 76 extends outwardly from the distal tongued edge 74 in a direction away from the vertical corner 66. The flanged panel 64 extends from the vertical corner 66 to a distal flanged edge 78. Each second corner structure 18 has an outer surface 77 (FIG. 2) and an inner surface 79 facing the payload. An outer flange 80, so called because it can be considered an extension of the outer surface 77, extends from the distal flanged edge 78 in a direction away from the vertical corner 66 and defines an inner notch 81 on the inner surface 79 of the flanged panel 64.

Also like the first corner structures 16, each second corner structure 18 comprises an L-shaped footer 52 extending inwardly from the tongued panel 62 and the flanged panel 64 near the bottom edge 48 and terminating in a distal edge 51. Each footer 52 has an L-shaped top surface 53 that slopes downwardly toward the distal edge 51. Each footer 52 is configured to extend underneath the upper portion 20 of the base 12 and mate with the base 12 in “skin to skin” fashion as explained below with regard to FIG. 7.

FIG. 6 is a perspective close up view of a portion of the pallet shipper 10 of FIG. 1 illustrating the tongue and groove method of attaching adjoining corner structures 16, 18. The groove 56 in each first corner structure is configured to receive a tongue 76 in an adjacent second corner structure 18 to form a tongue and groove seam 47.

FIG. 7 is a bottom perspective view of the pallet shipper 10 of FIG. 1, showing how the footers 52 mate with the base 12. Preferably the slope of the footers 52 is equal to the slope of the ledge 31 of the base 12 so that the top surface 53 of each footer 52 mates with (abuts) the underside 32 of the ledge. Also, the length of the footers 52 may be equal to the depth of the ledge 31 so that the distal edge 51 of each footer 52 mates with one of the 34, 36, 38, 40 edges of the lower portion 22 of the base 12.

FIG. 8 is a perspective view of a portion of the pallet shipper 10 of FIG. 1 and FIG. 9 is a bottom perspective view of the quarter PMC pallet shipper 10 of FIG. 1, both illustrating the cooperating flange method of attaching adjoining corner structures 16, 18. The inner flange 60 of each first corner structure 16 is configured to mate with a corresponding outer flange 80 of an adjacent second corner structure 18, thereby forming a convoluted “cooperating flange” seam 49 which minimizes or eliminates edge leaks. The convoluted seam or junction presents a tortuous, non-linear path for heat to transfer through the pallet shipper wall.

In the illustrated examples the first corner structure 16 comprises an inner flange 60 and the second corner structure 18 comprises an outer flange 80. However, it should be understood that a reverse configuration is also contemplated in which the first corner structure 16 comprises an outer flange and the second corner structure 18 comprises an inner flange. In either case, the flanges 60, 80 cooperate (join together) to form a convoluted but air tight seal.

The pallet shipper described herein is modular in that it can easily be expanded into a larger pallet shipper. FIG. 10 is a perspective view of another, larger embodiment of a pallet shipper 110 according to the disclosure. Like the previous embodiment, the pallet shipper 110 comprises a substantially rectangular base 112 (FIG. 11), a substantially rectangular lid 114, two substantially L-shaped, unitary, first corner structures 16 and two substantially L-shaped, unitary, second corner structures 18. The first corner structures 16 and the second corner structures 18 may be identical to that of the earlier embodiment. The base 112 may be a single unitary structure or may comprise two smaller bases 12 fitted together. Likewise, the lid 114 may be a single unitary structure or may comprise two smaller lids 14 fitted together.

In addition to the aforementioned components which the large pallet shipper 110 may share in common with the earlier embodiment, the large pallet shipper 110 further comprises two substantially rectangular sidewall panel 120. As best shown in FIG. 12, each sidewall panel 120 comprises a main panel 122, a footer 124 and tongues 126. The main panel 122 extends from a bottom edge 48 to a top edge 50 and from one side edge 130 to an opposite side edge 130. A tongue 126 extends outward from each side edge 130.

FIG. 11 is an exploded perspective view of the large pallet shipper 110 of FIG. 10. The large pallet shipper 110 may be made by adding a sidewall panel 120 between two adjacent corner structures 16, 118 on the tongue-in-groove sides of the small pallet shipper 10 (as opposed to the cooperating flange sides).

Since the sidewall 120 has tongues 120 on either side, it is necessary in this embodiment to modify the pallet shipper 10 of FIGS. 1-9. Specifically, the second corner structure 18 must be modified so that its distal (tongued) edge 74 defines a groove 119 for receiving a corresponding tongue 126 of an adjacent sidewall panel 120. This may be accomplished by modifying the tooling used to form the second corner structure 18 so that a modified second corner structure 118 is formed having a groove 119 along one edge. More specifically, the modified second corner structure 118 comprises a grooved panel 132 and a second flanged panel 134 orthogonal to the grooved panel 132 joined along a vertical corner 136. The second flanged panel 134 terminates in a second flange 138 at its distal end. (Alternatively, the sidewall 120 may be formed with a tongued edge and a grooved edge, which would negate the necessity to modify the second corner structures 18.)

In the embodiment shown in FIGS. 10 and 11, one sidewall tongue 126 is inserted into a groove 119 in an adjacent second corner structure 118 and the opposite tongue 126 is inserted into a groove 56 in a first corner structure 16. In this way the short sides of the small pallet shipper 10 become the long sides of the large pallet shipper 110. Because of the footers extending inward from the bottom edge 48 of the sidewall 120, each sidewall 120 is self-standing. Also, a sidewall 120 can be used on either side of the pallet shipper 110.

The pallet shipper 110 may covered with a single large lid or, as shown in FIG. 11, two smaller lids 14.

FIG. 13 is an exploded partial perspective view of a pallet shipper 10 with wire racks according to another embodiment of the disclosure. In addition to the components described above with regard to FIGS. 1 to 9, the pallet shipper 10 further comprises one or more self-standing bottom wire racks 82 having a payload bearing surface 84 located within the payload section. The pallet shipper 10 may further comprise refrigerants (not shown) located between the bottom wire rack 82 and the base 12.

The pallet shipper 10 may also comprise a top wire rack 88 having a refrigerant bearing surface 90 located within the payload section. Refrigerants (not shown) may be placed between the top wire rack 88 and the lid 14.

Alternative Embodiment

FIG. 14 is a perspective view of an alternative container 140 having solid corners and convoluted seams on all four sides. FIG. 15 is a perspective view of the same container 140 shown with a corner structure 148 and the lid 141 removed for clarity.

The container 140 comprises two substantially L-shaped first corner structures 146, two substantially L-shaped second corner structures 148, a base 150 having two pairs of diagonally opposing corners 151, and a lid 141. The container corner structures 146, 148 form a bottom edge 158 and a top edge 160. Like the previously described containers, the container 140 may or may not be used in conjunction with a pallet.

Each first corner structure 146 comprises first and second panels 152, 154 joined together along a vertical corner 142 to form a single unitary L-shaped structure. Each first corner structure 146 extends from the bottom edge 158 to the top edge 160. The first panel 152 extends from the vertical corner 142 to a flanged edge 153 having an outwardly extending flange 157. The second panel 154 extends from the vertical corner 142 to a notched edge 155 defining a vertically oriented notch 156.

Likewise, each second corner structure 148 comprises first and second panels 162, 164 joined together along a vertical corner 144 to form a single unitary L-shaped structure. Each second corner structure 148 extends from the bottom edge 158 to the top edge 160. The first panel 162 extends from the vertical corner 144 to a flanged edge 163 having an outwardly extending flange 167. The second panel 164 extends from the vertical corner 144 to a notched edge 165. The notched edge 165 defines a vertically oriented notch 166 (obscured in FIG. 15).

The vertical corners 142, 144 are solid corners, meaning they lack any seams or other discontinuities. The seams 169 are located on each vertical side of the container 140, away from the corners. Making the seams 169 convoluted and moving them away from the vertical corners 142, 144, for example, in the middle of the container sides, greatly reduces heat transfer between the outside and the inner (payload) compartment.

The flanged edge 153 of each first corner structure 146 is configured to mate with a corresponding notched edge 165 of an adjacent second corner structure 148, thereby forming a convoluted seam 169. Likewise, the flanged edge 163 of each second corner structure 148 is configured to mate with a corresponding notched edge 155 of an adjacent first corner structure 146, thereby forming another convoluted seam 169. The convoluted seams 169 present a tortuous, non-linear path for heat to transfer through the container wall.

As used herein the term “flange” refers to any projecting structure, that is, a structure that projects outwardly from an edge of a panel, including a tongue or a tab. The term “notch” refers to any inwardly extending space, that is, a space the extends inwardly from an edge of a panel to accommodate a flange, including a groove or slot. The term “convoluted seam” includes any seam in which a flange of one corner structure mates with the notch of another corner structure to form a tortuous, non-planar, mating surface. Preferably there are no gaps in the seam between the two corner structures.

Thus, a container 140 according to this disclosure may include four convoluted seams 169, each comprising a flanged edge 153, 163 configured to mate with a notched edge 155, 165. Like the flanged seams 49 and tongue and groove seams 47 described above with respect to other embodiments, the convoluted seams 169 minimize or eliminate edge leaks by presenting a tortuous, non-planar path for heat to transfer through the pallet shipper wall.

The lid 141 may fit snugly onto the top rim 160 of the joined corner structures 146, 148. The base 150 has a perimeter that may nest within grooves 161 defined by and located near the bottom of each corner structure 146, 148.

It will be appreciated that, if the container 140 has a square profile, that is, the container 140 has four sides of equal width, the first corner structures 146 and the second corner structures 148 may be identical. In making such a container 140, the same tool may be used to make all four corner structures 146, 148.

Refrigerant Height Adjustment Feature

As in the previously described embodiments a rack 88 for holding refrigerants, such as the rack 88 shown in FIG. 13, may be located within the payload section. The rack 88 may be placed at various heights. For example, referring to FIG. 15, the rack may be placed on top of the inwardly extending ledge 181 or in a groove 182 located below the ledge 181.

Living Hinges

The corner structures described herein may have vertical corners that function as living hinges to enable the corner structures to be shipped flat and then bent into an L-shape during assembly of the container. For example, FIG. 16 is a perspective view of a corner structure 170 comprising a first panel 172 joined to a second panel 174 along a vertical corner 176 to form a single unitary structure. The vertical corner 176 functions as a living hinge, enabling the corner structure 170 to move between the L-shaped configuration shown in FIG. 16 and the flat configuration shown in FIG. 17.

Alternative Embodiment—U-Shaped Structures

FIG. 18 is a top view of another alternative container 180 with the lid removed. The container 180 comprises two U-shaped structures 182, 184 that mate to form two convoluted seams 186 on opposite sides. If the container 180 has a square profile like that shown in FIG. 18, the U-shaped structures 182, 184 may be identical. The vertical corners 188 may function as living hinges. The first U-shaped structure 182 and the second U-shaped structure may be joined to a base 190 in a fashion similar to that described above for the other embodiments.

INDUSTRIAL APPLICABILITY

The thermally insulated pallet shipper may be used in any industry where temperature sensitive products are shipped, including but not limited to the pharmaceutical, hospital and food industries, particularly for shipping payloads by air.

The pallet shipper may be made in any suitable size, including the following industry recognized sizes:

Size Dimensions PMC-quarter 61.5″ × 47″ PMC-half 61.5″ × 94″ PAG-quarter 61.5″ × 44″ PAG-half 61.5″ × 88″ European Union (E.U.)   47″ × 39″ U.S.   48″ × 40″

The pallet shipper may be any suitable height, but typically is 64″ or less including all the outer accessories (skid, trays, plastic wrap etc.).

The pallet shipper components may be made of any suitable materials, but preferably are made from polymeric foam materials, including Neopor, ARCEL, EPS, EPP, XPS, PUR and other thermoplastic and thermoset foam materials.

The pallet shipper has no spit edges. The L shapes corner structures completely eliminate edges and therefore the pallet shipper has no edge leaks.

The “split edges” in the present pallet shipper are moved towards center of each sidewall. The tongue and grove feature creates a tortuous path to reduce heat loss. The tongue and grove feature also creates a locking mechanism for the walls. The center of each wall may also be protected from the inside using refrigerants by lining up refrigerants against the interior walls.

The pallet shipper is easy to assemble and has self-standing wall feature. All the walls are self-supporting which speeds up the assembly process. Due to the self-standing feature the entire shipper 10, 110 can be assembled by one person. Due to the self-standing wall features, there can be no mix up between the left walls and right walls, which can speed up shipper assembly, thus minimizing the time any refrigerants are exposed to room temperature

Creating a tortuous path at each tongue and groove seam or junction and at each flanged seam or junction delays any loss of heat. The disclosed pallet shipper 10, 110 has L-shapes corner structures 16, 18 where the footer 52 of the wall slides under the base 12, thus creating another long tortuous path to minimize heat transfer.

The pallet shipper 10, 110 has a modular design where a small pallet shipper 10 can be extended from, say, a quarter PMC to a half PMC and from a quarter PAG to a half PAG by just adding one extra sidewall 120 between 2 L-shaped corner structures 16, 18. This modular design has many advantages:

-   -   1. Reduction in tooling cost. Adding on extra panel 120 requires         just one extra tool compared to building entire set with six         different new tools.     -   2. Reduction in tooling cost results in an overall cost         reduction for the final product.     -   3. Customers can also interchange parts between the same family         (PMC and PAG) of shippers for better logistics.     -   4. Maintain overall ease of assembly. Customer doesn't have to         change any assembly process.

The pallet shipper may achieve a 37% weight reduction when compared material to material:

Half PMC 92 lbs. in 148 lbs. in EPS sleeved PUR Quarter PMC 56 lbs. in  89 lbs. in EPS sleeved PUR

It is understood that the embodiments of the disclosure described above are only particular examples which serve to illustrate the principles of the disclosure. Modifications and alternative embodiments of the disclosure are contemplated which do not depart from the scope of the disclosure as defined by the foregoing teachings and appended claims. It is intended that the claims cover all such modifications and alternative embodiments that fall within their scope. 

What is claimed is:
 1. A container comprising: first and second U-shaped structures that mate to form two convoluted seams on opposite sides of the container.
 2. The container of claim 1 wherein: the container has a square profile and the U-shaped structures are substantially identical.
 3. The container of claim 1 wherein: first and second U-shaped structures comprise vertical corners that form living hinges.
 4. The container of claim 1 wherein: the first U-shaped structure and the second U-shaped structure are joined to a base.
 5. A container comprising: a first substantially U-shaped, unitary structure comprising a first end panel and two first side panels, each first side panel joined to the first end panel along a respective one of two vertical corners to form a single, unitary first U-shaped structure, each first side panel extending from a respective one of the first vertical corners to a first distal edge; a second substantially U-shaped, unitary structure comprising a second end panel and two second side panels, each second side panel joined to the second end panel along a respective one of two second vertical corners to form a single, unitary second U-shaped structure, each second side panel extending from a respective one of the second vertical corners to a second distal edge; wherein: the vertical corners are solid, continuous corners; and each first distal edge is joined to a respective second distal edge along a convoluted seam.
 6. The container of claim 5 further comprising: a substantially rectangular base joined to the first and second U-shaped structures.
 7. The container of claim 6 wherein: the base has a perimeter that nests within grooves defined by each of the first and second U-shaped structures.
 8. The container of claim 6 further comprising: a top edge defined by the first and second U-shaped structures; and a lid fitted onto the top edge.
 9. The container of claim 5 wherein: each convoluted seam is formed by a flange extending outwardly from one distal edge into a notch defined by an opposing distal edge.
 10. The container of claim 5 wherein: the first and second U-shaped structures are substantially identical.
 11. The container of claim 10 wherein: the vertical corners comprise living hinges so that the first and second U-shaped structures are moveable between a flat configuration and a U-shape configuration. 